Share-Based Compensation Plans (Details 5) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Option [Member]
Weighted-average assumptions used for options granted
Expected dividends	1.90%	2.10%	2.20%
Expected volatility	29.10%	35.10%	40.70%
Risk-free interest rate	1.30%	0.70%	0.60%
Expected term in years	4 years 3 months 17 days	4 years 3 months 17 days	3 years 8 months 12 days
Grant-date fair value	$ 14.99	$ 13.97	$ 14.07
Employee Stock Purchase Plan [Member]
Weighted-average assumptions used for options granted
Expected dividends	1.70%	2.20%	2.70%
Expected volatility	20.30%	28.00%	32.70%
Risk-free interest rate	0.00%	0.10%	0.10%
Expected term in years	3 months	3 months	3 months
Grant-date fair value	$ 15.53	$ 11.73	$ 9.53